The Remember package by John Wiegley lets you store quick notes with little
interruption of your work flow. It is an excellent way to add new notes and
tasks to Org files. The remember.el package is part of Emacs 23, not
Emacs 22. See http://www.emacswiki.org/cgi-bin/wiki/RememberMode for
more information.
Org significantly expands the possibilities of Remember: you may define templates for different note types, and associate target files and headlines with specific templates. It also allows you to select the location where a note should be stored interactively, on the fly.